Distinguishing two single-mode Gaussian states by homodyne detection: An information-theoretic approach Academic Article uri icon


  • It is known that quantum fidelity, as a measure of the closeness of two quantum states, is operationally equivalent to the minimal overlap of the probability distributions of the two states over all possible positive-operator-valued measures (POVM's); the POVM realizing the minimum is optimal. We consider the ability of homodyne detection to distinguish two single-mode Gaussian states and investigate to what extent it is optimal in this information-theoretic sense. We completely identify the conditions under which homodyne detection makes an optimal distinction between two single-mode Gaussian states of the same mean and show that, if the Gaussian states are pure, they are always optimally distinguished. 2005 The American Physical Society.

published proceedings


author list (cited authors)

  • Nha, H., & Carmichael, H. J.

citation count

  • 29

complete list of authors

  • Nha, H||Carmichael, HJ

publication date

  • March 2005